Re: [boost] fixed-point math library?

From: Michael Marcin (mike_at_[hidden])
Date: 2006-09-03 06:21:45

"Michael Marcin" <mmarcin_at_[hidden]> wrote in message
news:<ecg4ib$d6h$1_at_[hidden]>...
> Does boost have a fixed-point math library?
> 

I guess not.  

I wrote something to suit my immediate needs.
This is my first try at writing boost-like code.
I'd appreciate suggestions/criticism.

One thing I'd like to do is add optional over/underflow, but I'm not sure
how
I'll do that yet.  For another I think I should specialize
std::numeric_limits 
for the fixed type, but I'm not sure what to put for a lot of the entries as

I've only ever needed min() and max() myself.

Thanks,

Michael Marcin
Method Solutions, Programmer 

// a simple function to instantiate my definitions
void instatiate_fixed()
{
        using namespace boostish::math;
        typedef fixed<16,16> fx16_16;
        fx16_16 testint(5);
        fx16_16 testfloat(5.0f);
        fx16_16 testdouble(5.0);
        fx16_16 test = fx16_16(5); // copy constructions
        test = fx16_16(5); // assignment 
        assert( test < fx16_16(6) ); // less than compare
        assert( test == fx16_16(5) ); // equality compare
        test += fx16_16(5); // addition and assignment
        test -= fx16_16(5); // subtraction and assignment
        test *= fx16_16(5); // multiplication and assignment
        test /= fx16_16(5); // division and assignment
        ++test; // prefix increment
        --test; // prefix decrement
        test *= 5; // integer multiplication and assignment
        test /= 5; // integer division and assignment
        test = test * 5; // integer multiplication
        test = 5 * test; // commutative integer multiplication
        test = test / 25; // integer division
        assert( to_integer(test) == 5 ); // conversion to integer
        assert( to_float(test) == 5.0f ); // conversion to float
        assert( to_double(test) == 5.0 ); // conversion to double
        fx16_16 raw = as_fixed( 1<<16 );// raw fixed-point number to wrapped
fixed-point
        assert( raw == fx16_16(1) );
}

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